Provided is an expansion valve for a vehicle air conditioning device in which a coolant flowing in from a condenser is throttled and supplied to an evaporator, and the degree of opening is controlled by means of the coolant flowing in from the evaporator and flowing out to a compressor, wherein the expansion valve comprises a main valve body formed with: a throttling flow pathway which has a first port for the inflow of the coolant from the condenser and a second port formed in a first side surface in order to supply the throttled coolant to the evaporator in the bottom surface, and on the inside of which the coolant that has flowed in to the first port is throttled; and an internal flow pathway which is formed in line with the throttling flow pathway and connects through to the first port such that the coolant that has flowed in to the first port flows out to the throttling flow pathway. Consequently, it is easy to process the main valve body, and hence production is straightforward and costs can be reduced.