An image forming device includes a driving mechanism that transmits a driving force to a process cartridge through an input portion of the process cartridge. The driving mechanism includes a drive shaft shifting between a state engaging with the input portion and a state spaced from the input portion, a first cam joined with a door to be rotated with movement of the door, the first cam including a first sliding surface, a translation member including a sliding contact portion which slidably contacts the first sliding surface, the translation member being configured to engage with the drive shaft and shift together with the drive shaft with the sliding contact portion sliding on the first sliding surface with rotation of the first cam, and a second cam including a second sliding surface which slidably contacts the sliding contact portion to face the first sliding surface through the sliding contact portion.