Kitchen cleaning

I have two questions.
1)What is the The exhaust fan in the kitchen(one above the gas range) called in japanese.
2)One that I have in my apartment has become very very dirty.One who used it previously obviously did not clean it even once.How do I clean it?Are there any specific cleaners available in the supermarket?Are there any professional cleaning agaencies here in Tokyo? How much do they charge?

1)Exhaust fan is "Kanki-sen (換気扇）" in Japanese.

2)Cleaning a fan is the least I want to do as a housewife! Anyway, the most popular solution would be "Magiclean (マジックリン)." You can find it at most supermarkets/drug stores.
See this picture:
http://www.kao.com/jp/magiclean/mcl_handy_spray_00.html

If you can remove parts, do it and soak them into diluted solution for 20-30 min. (Magiclean plus lukewarm water) When the dirt becomes loose, clean the surface with sponge/dustcloth. Since Magiclean is very strong, wear lubber gloves when you use it.

For unremovable parts, soak paper towel into the solution and put it over the parts.

Professional service costs you 8000-10000 yen.
http://www.osoujihonpo.com/person/fan.html

Thanks a million JLady. Since I live in Kodan I went to the kanri office and told them my problem about kankisen(thanks to you they got it immediately).And they said I better do it myself since the professional servicec cost around 10000 yen.She called up few such services for me and the range was 9000 yen to 20000 yen.So it looks like I need to do it myself.Fortumnately I do have that spray at my house though I had never had a chance to use it.Will find out how to remove the parts and clean it.Thanks for such a detailed reply.

Not at all! It seems that your Kodan has a very nice staff in the office. Just make sure that you've unplugged the fan before starting the job (to prevent unexpected movement). Good luck!