The invention relates to an encapsulated piezoelectric resonator device comprising an oscillating member having a quartz member and a frame integral with and surrounding the quartz member, the frame having two connecting faces, electrodes on the quartz member, and two cover members, each having a central depression defining a frame provided with a connecting face, each connecting face of the oscillating member being bonded with the connecting face of the cover member for sandwiching the oscillating member between the cover members.The invention also relates to a method for manufacturing such an encapsulated piezoelectric resonator device comprising the steps of machining a quartz plate by photolithography for making at least one oscillating member, forming electrodes on the quartz member, making at least two cover members having central depressions defining their peripheral frames and bonding the oscillating member with two cover members by their frames.