Abstract: A vibrating apparatus e.g. for shaking the forming wire of a paper machine, comprising a body (1) and a drive shaft (2) rotatably mounted in the body. The drive shaft supports an eccentric bushing (3) displaceable along but nonrotatably fixed to said drive shaft. A reciprocating rod (9) positioned transversely with respect to the drive shaft is provided with a ring-shaped end (10) rotatably mounted around an outer mantle surface of said bushing stationary in the axial direction (D) of said bushing. The apparatus further comprises adjusting means (11-20) for displacing said bushing along the drive shaft in its axial direction in order to adjust the eccentricity between the drive shaft and the ring-shaped end of the reciprocating rod.