An image forming apparatus includes: a housing part that is capable of housing a plurality of recording materials in such a manner that one recording material is put on another; a transport part that transports a recording material from the housing part; and a hardware processor that detects a kind of the recording material transported by the transport part, detects an amount of the recording materials housed in the housing part, detects replacement of recording materials housed in the housing part, or addition of recording materials in the housing part, on the basis of a result of the detection by the hardware processor, and, on the basis of a result of the detection by the hardware processor, switches whether or not to execute, by the hardware processor, the kind detection of the recording materials housed in the housing part.