To provide a crystal holder which prevents occurrence of a positional shift among members due to rotation of locking screws after completion of the angle adjustment of a crystal.

A shoulder bolt 52 is inserted into the through-hole 27 of a first angle adjusting member 14 and its tip is screwed into the threaded hole 20 of a crystal holding member 12 and thereby both the members are freely rotatably engaged with each other. The tip of an adjusting screw 46 fixed to the angle adjusting member 14 is screwed to the cylindrical nut 21 of the crystal holding member 12, and then the crystal holding member 12 rotates around the shoulder bolt 52 as an axis. The through-hole 27 of the angle adjusting member 14 is provided with a small-diameter portion 56 into which the shank 52b of the shoulder bolt is freely rotatably inserted, a middle-diameter portion 57 in which a head 52a is housed and a large-diameter portion 58 which houses a locking washer 53. The locking washer 53 is pressed by the head of a locking screw 55 to a second stepped portion 60, and thereby the crystal holding member 12 and the first angle adjusting member 14 are fixed to each other.