Abstract: An instrument for giving patting treatment to a user's shoulder or the like body part to promote blood circulation in stiffened muscle. In a housing of the instrument's body having an aperture, stationary electromagnet part defining an axial space is fixed aligning the space with the housing aperture and freely movable plunger is disposed to extend in the axial space so that, as electromagnetically attracted at an end inside the housing to a magnetized core end due to energization of coil of the stationary electromagnet part, the plunger extracts out of the housing with the other end located in the housing aperture and having a treating attachment with which the instrument is butted to the body part substantially vertically with its weight applying to the latter through the attachment, so as to raise the instrument's body relatively upward and, upon de-energization of the coil, the instrument's body falls down to hit upon the attachment to give the patting treatment to the body part.