Gas sensor

摘要

A gas sensor including an element 4 for measuring the concentration of a gas to be detected which is contained in a gas under measurement; a protector 2 provided to cover a tip end of the element 4 in the axial direction; and a protection cap 1 removably attached to the gas sensor. The protection cap 1 includes a tubular portion 106 which surrounds a side surface 202 of the protector 2, support portions 102 which project from an inner surface 161 of the tubular portion 106 and reach the side surface 202 of the protector 2 without axially partitioning the space between the inner surface 161 of the tubular portion 106 and the side surface 202 of the protector 2, and an air-outlet hole 103 for establishing communication between the interior and exterior of the protection cap 1.