To provide a press-in device capable of improving efficiency in press-in work, while securing high press-in accuracy of a press-in object in pressing the press-in object into a press-in part of an object.

This press-in device 1 for pressing a valve guide of a suction-exhaust valve in a press-in hole of a cylinder head 3 of an internal combustion engine, includes a placing base 20 for placing the cylinder head 3, a press machine 10 having a pair of operation levers 15 and 16 operated by both hands by a worker, a support mechanism capable of supporting the placing base 20 in a floating state, a grip 25 arranged on the placing base 20 and first and second buttons 51 and 52 for operating the support mechanism in a floating form of supporting the placing base 20 in the floating state and a positioning form of positioning the placing base 20 to a table 12. The first button 51 is arranged in the grip 25 in a range capable of simultaneous operation with moving operation of the placing base 20 by the grip 25 by one hand. The second button 52 is arranged in the vicinity of a gripping part 15a of the operation lever 15 in a range capable of simultaneous operation with operation of the operation lever 15 by one hand.