To provide a power damper for a high power laser capable of preventing the power damper from melting damage due to concentration of laser power locally on a laser light receiver, a laser power meter thereof and a laser power measuring method with using the power meter.

The power damper which makes a light receiver absorb the laser power of laser beam irradiated inside light receiver having a hollow rectangular parallelepiped shape by converting to heat has a light receiver position controller for introducing the laser beam inclined against a center axis and shifted to the direction perpendicular to the center axis. In the laser power measuring method, the laser beams proceeding after multiple reflection on the inner plane of the rectangular parallelepiped is made not to overlap to each other in the longitudinal direction for 1.5 times return or more.