To provide an expansion valve capable of correctly transferring heat to a power element, and adjusting the time constant without increasing the cost.

An equalizing hole 13 is communicated with an equalizing chamber adjacent to a low pressure passage between connection holes 22 and 23 of a valve case 3 immediately below a diaphragm 6 of a power element 1 in a direction orthogonal to the refrigerant flow direction of the low pressure passage. The equalizing hole 13 is formed by cutting out the outer circumference of a holder 12 to be welded to an opening edge portion of a lower housing 5, and the opening area is set according to the time constant to be temperature-sensed by the power element. Since refrigerant in the low pressure passage directly passes through the equalizing chamber via the equalizing hole 13, the power element 1 can correctly sense the temperature of the refrigerant, and the time constant to be temperature-sensed by the power element can be easily adjusted only by changing the opening area of the equalizing hole 13.