To enable preventing of excessive spray of water in a vaporizer inexpensively without employing a large flow control valve with a higher flow rate controlling performance as branch tube.

In this vaporization equipment, a liquefied natural gas 6 is vaporized by an open-rack type vaporizer 5 using seawater 3 as heat source. In this case, an adjusting valve 19 is provided in a drain system 9 for draining residual seawater 3 during the cessation of the operation of the vaporizer 5 and a controller 21 is provided to output a command signal 18 to the adjusting valve 19 so that an excess of flow rate of the seawater 3 over a rated flow rate of the evaporator 5 can be drained from the drain system 9 based on a flow rate signal 20 from the existing flowmeter 10 provided on a branch tube 4 for the operational control of the equipment as a whole.