A personal hygiene device, extending in a 3-dimensional space that is spanned by a x-y-z coordinate system, comprising: a drive unit having a support; a stator fixedly mounted at the support; an armature that is spring-mounted at the support for driven linear oscillating motion along a first longitudinal direction that is parallel to or coincides with the x-axis of the x-y-z coordinate system, the armature having a center of gravity located in rest at a coordinate [x a; y a; z a]; and a drive shaft fixedly coupled with the armature, the drive shaft having a center of gravity located in rest at a coordinate [x d; y d; z d]; a first treatment head assembly detachably connected to the drive shaft, the first treatment assembly having a center of gravity located in rest at a coordinate [x t1; y t1; z t1]; and a secondary mass element spring-mounted at the support for essentially linear oscillating motion along the first longitudinal direction, the secondary mass element having a center of gravity located in rest at a coordinate [x m; y m; z m]; wherein at least the coordinate [x a; y a; z a] of the center of gravity of the armature has an offset in at least one of the y-direction and z-direction with respect to the coordinate [x d; y d; z d] of the center of gravity of the drive shaft or with respect to the coordinate [x t1; y t1; z t1] of the center of gravity of the first treatment head assembly, i.e. y a ≠ y d and/or y a ≠ y t1 and/or z a ≠ z d and/or z a ≠ z t1, and the secondary mass element is designed such that the coordinate [x m; y m; z m] of the center of gravity of the secondary mass element is aligned with the coordinate [x j; y j; z j] of the joint center of gravity of the drive shaft, the first treatment head assembly and the armature in the at least one offset direction, i.e. y m = y j and z m = z j, so that a line connecting the coordinate [x m; y m; z m] of the center of gravity of the secondary mass element and the coordinate [x j; y j; z j] of the joint center of gravity is parallel to or coincides with the x-axis. a drive unit having a support; a stator fixedly mounted at the support; an armature that is spring-mounted at the support for driven linear oscillating motion along a first longitudinal direction that is parallel to or coincides with the x-axis of the x-y-z coordinate system, the armature having a center of gravity located in rest at a coordinate [x a; y a; z a]; and a drive shaft fixedly coupled with the armature, the drive shaft having a center of gravity located in rest at a coordinate [x d; y d; z d]; a support; a stator fixedly mounted at the support; an armature that is spring-mounted at the support for driven linear oscillating motion along a first longitudinal direction that is parallel to or coincides with the x-axis of the x-y-z coordinate system, the armature having a center of gravity located in rest at a coordinate [x a; y a; z a]; and a drive shaft fixedly coupled with the armature, the drive shaft having a center of gravity located in rest at a coordinate [x d; y d; z d]; a first treatment head assembly detachably connected to the drive shaft, the first treatment assembly having a center of gravity located in rest at a coordinate [x t1; y t1; z t1]; and a secondary mass element spring-mounted at the support for essentially linear oscillating motion along the first longitudinal direction, the secondary mass element having a center of gravity located in rest at a coordinate [x m; y m; z m]; wherein at least the coordinate [x a; y a; z a] of the center of gravity of the armature has an offset in at least one of the y-direction and z-direction with respect to the coordinate [x d; y d; z d] of the center of gravity of the drive shaft or with respect to the coordinate [x t1; y t1; z t1] of the center of gravity of the first treatment head assembly, i.e. y a ≠ y d and/or y a ≠ y t1 and/or z a ≠ z d and/or z a ≠ z t1, and the secondary mass element is designed such that the coordinate [x m; y m; z m] of the center of gravity of the secondary mass element is aligned with the coordinate [x j; y j; z j] of the joint center of gravity of the drive shaft, the first treatment head assembly and the armature in the at least one offset direction, i.e. y m = y j and z m = z j, so that a line connecting the coordinate [x m; y m; z m] of the center of gravity of the secondary mass element and the coordinate [x j; y j; z j] of the joint center of gravity is parallel to or coincides with the x-axis.