Method of manufacturing a quartz resonator

A method of manufacturing a quartz resonator, including etching a quartz substrate, forming a quartz piece in a shape of a tuning fork in which two vibrating arms extend from a base, and forming electrodes in areas including side surfaces inside the vibrating arms of said quartz piece, comprising the steps of:

• forming said quartz substrate by bonding main surfaces of two sheets of original plates, which are made of quartz crystal, and main surfaces thereof are orthogonal to the direction of a Z axis, a crystal axis, so that the plus/minus directions of a X axis, another crystal axis, are made in a reverse relation to each other;
• forming an outer shape of the quartz piece by forming masks for the outer shape, through which the surfaces of the quartz substrate are exposed, on both front and back surfaces of said quartz substrate in a manner that the mask follows along the outer shape of said quartz piece and a width direction of the outer shape agrees with said X axis, and by etching the quartz substrate;
• forming a metal film to form said electrodes in areas including a crotch portion sandwiched between the side surface inside the respective vibrating arms and the respective vibrating arms of the quartz piece, after removing said mask for the outer shape;
• covering said metal film with a positive type resist film, of which exposed portion changes to be soluble;
• forming a resist pattern in which the metal film in the areas including said crotch portion is exposed, by exposing and developing said resist film using a mask to form electrode patterns to remove the exposed portions;
• and
• then, etching said metal film using the resist pattern to form electrodes.