Do you have any idea when the book was printed? If it's within the last couple of decades it might be worth trying to track down a clean light weight digital typewriter. IIRC there are some possibles that are not at Myfonts.
Don

Hi Don, Thanks for your reply. The book was printed in France in 1984… http://www.mfj.gr.jp/publications/mfj/iki_no_kozo_structure_de_liki/inde... Maybe the text was really typewrited ?

Yes, in 1984 some books were typed on an IBM Selectric typewriter, or a similar good quality typewriter from another source and the results were photographed for printing. Note the handwritten Greek phrase.
We can check the design against some of the popular typefaces used on IBM "elements" -- the thing that looks like a golfball -- and see if it is digitized. They had names like _courier_, _prestige_, _elite_ etc.
Here is a selection of these typefaces compiled by Luc Devroye http://luc.devroye.org/fonts-44934.html If you can find some of the distinctive letters in the book, like _Q_, _R_, _g_ and _3_ it makes it easier to decide on a match.
Don

Hi Don, thanks for your reply and for the link. A friend of mine found the font ! Like you say it comes from a IBM Selectric typewriter : it's called Delegate (look at the K, it matches : https://dl.dropboxusercontent.com/u/2425128/Screenshot%202014-10-02%20%C... !). My friend says there is not clean digitized version of this font -- just this dirty free one : http://www.azfonts.net/load_font/delegate.html ! But some specimen exist, so we think about digitizing it in the future ;-)

Or this one called Triplicate by Matthew But­t­er­ick : http://practicaltypography.com/triplicate.html

Here is a list of reasonably well engineered monospace typewriter fonts at Myfonts, that could perhaps be substituted. None is a proper match for Delegate.

First, several fonts based on IBM'S Prestige for the Selectric
Prestige Elite, several sellers including
http://www.myfonts.com/fonts/linotype/prestige-elite/
Alix FB
http://www.myfonts.com/fonts/fontbureau/alix-fb/
Prestige 12 Pitch, also based on IBM'S Prestige for the Selectric
http://www.myfonts.com/fonts/bitstream/prestige-12-pitch/

Also-rans, in alphabetical order:
Bulletin Typewriter
http://www.myfonts.com/fonts/itfmecanorma/bulletin-typewriter/
EF Techno Script, apparently based on a Royal typewriter
http://www.myfonts.com/fonts/itfmecanorma/bulletin-typewriter/
ITC American Typewriter, century old design
http://www.myfonts.com/fonts/adobe/itc-american-typewriter/
Italian Typewriter, Ollivetti circa 1940, more stylish than most
http://www.myfonts.com/fonts/flanker/italian-typewriter/
Remington Elite Typewriter
http://www.myfonts.com/fonts/intellecta/remington-elite-typewriter/
Remington Typewriter, with well designed Italic by Frederic Goudy
http://www.myfonts.com/fonts/lanston/ltc-remington-typewriter/
Smith Premier, an old ATF design, as Smith Premier NF
http://www.myfonts.com/fonts/nicksfonts/smith-premier-nf/
Tired of Courier
http://www.myfonts.com/fonts/ingrimayne/tiredofcourier/
Typewriter by Monotype, source unknown
https://www.myfonts.com/fonts/mti/typewriter-mt/
Plus, perhaps of lesser quality, Intellecta Typewriter, old design
http://www.myfonts.com/fonts/intellecta/intellecta-typewriter/
Don

Just to clarify my previous post.
My list of reasonably well engineered monospace typewriter fonts at Myfonts, that could perhaps be substituted for Delegate, was limited to fonts with a double story _g_. I did not include several similar quality fonts that have a single story _g_.
Don

Hi Don, sorry for the delay of my reaction, and thanks you so much for your links.
GG