To easily perform locking operation to fix an oscillation bracket in a pressed attitude, and unlocking operation.

In this photograph printer, a carrying mechanism 18 for carrying printing paper P from a printing paper storage part 11 toward an exposure operation part 4 is composed of a drive roller 31 and a press roller 32, the oscillation bracket 35 to support the press roller 32 is changeable between the pressed attitude in which the press roller 32 is pressed to the drive roller 31, and a released attitude in which it is released from the drive roller 31, and a lock mechanism is provided to fix the oscillation bracket 35 in the pressed attitude. The lock mechanism comprises a pair of arm members 37 capable of oscillating around a second axial core X2 disposed at each width end of the printing paper P close to a free end of the oscillation bracket 35, and a pair of lock members 40 provided on a photograph printer main body to lock hook parts 40 provided close to free ends of the arm members. A picking part 37G is provided to integrally oscillate with both of the arm members 37.