The present invention relates to a personal care device such as an electric hair cutter like shaver or toothbrush, and to a method of manufacturing such personal care device. More particularly, the personal care device comprises a handle and a function head supporting at least one personal care tool, said function head being attached to said handle, wherein at least one of said handle and said function head includes an outer metal shell formed in one piece with an integral, homogeneous, seamless structure having a ring-like or sleeve-like shape with closed annular cross-sections. Said outer metal shell includes at least one undercut portion which is formed with a hydraulic pressure forming step applying hydraulic pressure onto a side of a metal shell blank positioned in a mold to deform the metal shell blank and press an opposite side of the metal shell blank against said mold to adopt a contour of the mold.