Provided are a photoreceptor of an electophotographic system satisfactorily high in resistance to contamination with a developer or corona products and durability to a contact electrification unit or a cleaning blade and capable of preventing occurrence of film defects in the production, and a process cartridge and an image forming apparatus in which a good image quality can be obtained over a long period of time. The photoreceptor includes a conductive substrate and a silicon compound-containing layer located on the substrate and containing a cyclic siloxane compound and/or derivatives thereof. The cyclic siloxane compound has a cyclic structure containing a repeating unit represented by formula (1) ##STR1##

wherein A¹ and A², which may be the same or different, each represent a monovalent organic group.