An image forming apparatus, including an image forming section which forms image on a recording sheet based on image data, plural trays which accommodate the sheets to be supplied to the image forming section, a humidity detecting unit which detects humidity inside the paper tray, a dehumidifying device which dehumidify inside the paper tray, and a control section which controls the dehumidifying device and management of jobs, and controls the image forming section to execute the jobs, wherein if the humidity inside the paper tray to be used for a first priority job is higher than a predetermined value, the control section suspends execution of the first priority job, and the control section controls the image forming section to execute a reserved job which is executable from among reserved jobs with low priority order, before executing the first priority job.