An image forming apparatus includes a switching unit configured to switch a power supply source from a main power source to a power storage unit according to shifting to a power failure state, a calculation unit configured to calculate a power amount to be consumed by a received job if the power supply source is the power storage unit when the job is received, a detection unit configured to detect a power amount stored in the power storage unit, a determining unit configured to determine whether the received job can be executed based on the detected power amount and the calculated power amount to be consumed for the received job, and a control unit configured to start processing the job if it is determined that the received job can be executed and to perform control during the processing of the job so as not to accept a subsequently received job.