To provide a sleep mode control system restricting power consumption while an image forming apparatus (ifma) is in a sleep mode (slm) and allowing a user to deactivate the sleep mode without impairing his/her convenience. The sleep mode control system includes the imf entering the slm to reduce power consumption and a power generator provided below a passage floor on which the imf is mounted. The power generator has a power generation unit, when stepped, provides a private power generation and an electromotive force detection unit detecting an electromotive force generated at the power generation unit successively, generating a pulse signal using the resulting electromotive force, and outputting the resulting pulse signal successively. The ifma has a sleep control part deactivating the slm, while the ifma is being in the slm, based on a signal pattern of the pulse signal outputted from the electromotive force detection unit.