An image forming apparatus includes: a photoconductive drum on which an electrostatic latent image is formed. A developer develops the electrostatic latent image to form a toner image on the photoconductive drum. A transfer-fixer transfers the toner image from the photoconductive drum to a recording sheet and fixes the toner image on the recording sheet. A waste toner particle collector collects toner particles remaining in the developing section into a collection container. A toner amount detector detects the amount of toner particles collected in the collection container. A notifying portion notifies a user when the amount of toner detected reaches a predetermined observing amount. A collection amount setting portion enables a reduced collection amount to be set for the collection of waste toner particles in the developing section in accordance with an increase in the detected toner amount after the detected toner amount reaches the observing amount.