To reduce an occupied space of a liquefied gas evaporating device and reduce energy consumption during operation of the liquefied gas evaporating device.

The liquefied gas evaporating device is provided with an evaporation part case 1 having an LP gas inflow port 2 into which LP gas (liquid phase) 4 is flowed and an LP gas outflow port 3 to which vaporized gas is flowed out, and with heat pipes 7 fixed by making heat release parts 7b contact with a wall face of the evaporation part case 1. Swelling parts 6 projecting toward inside of the case 1 are formed on a bottom face 5 of the evaporation part case 1. The heat release parts 7b of the heat pipes 7 are embedded in the swelling parts 6 and fixed. At the time of fixing, heat transfer is facilitated by press-fitting the heat release parts 7b of the heat pipes 7 and filling spaces between the heat release parts 7b of the heat pipes 7 and the wall face of the case 1 with solder. Heat collecting fins 8 are fixed to heat input parts 7a of the heat pipes 7 to effectively collect heat.