To provide a vibration isolating structure, preferable for vibration isolation of an electric device mounted on a construction machine.

This vibration isolating structure of a construction machine includes: a traveling body (1); a frame (4) provided on the traveling body; a working device (3) disposed on the front of the frame (4); and a hollow counterweight (5) disposed on the back part of the frame (4) to move in the vertical direction. A rack (11) loaded with the electric device (10) is disposed in an internal space of the counterweight (5), the lower surface of the rack (11) and the frame (4) are connected to each other by a spring (12a), and the top face of the rack (11) and the counterweight (5) are connected to each other by a spring (12b). Thus, a dynamic vibration absorber is configured by the rack (11) as the main system and the counterweight (5) as an additional system.