Provided is a portable electronic device having improved degree of freedom in designing. A cellular phone 1 has a display part 9, a frame 44 holding the display part 9, and a case 7 having a peripheral wall portion 31b which forms an open portion 31c. The frame 44 can be mounted in the case 7 from the open portion 31c, is screwed to the peripheral wall portion 31b by a screw 79 inserted in a direction intersecting the mounting direction, and fixed to the case 7, with the display part 9 exposed at the open portion 31c.