A dry-shaving apparatus comprises a holder for a circular cutting unit which includes an external cutting member formed with hair-entry apertures, having an outwardly extending annular flange portion, and movable transversely relative to the holder, and an internal cutting member rotatably drivable relative to the external cutting member. A retaining plate is positioned inside the holder. The external cutting member is detachably secured to the retaining plate, the internal cutting member being retained between the external cutting member and the retaining plate, by means of two resilient arms engaging around the flange portion of the external cutting member and secured to the retaining plate. A spring associated with the retaining plate moves the same transversely relative to the holder.