PROBLEM TO BE SOLVED: To provide a powder dissolution device which can manage concentration of a solution precisely.SOLUTION: A powder dissolution device 1 includes: a measuring hopper 21 provided between a delivery passage 8 disposed on a powder storing tank 2 and a dissolution tank 4 a lower opening switching means 28 which switches a lower opening 21b of the measuring hopper a measuring means 23 which measures a weight of the measuring hopper an upper connection means 24A which connects an upper opening 21a of the measuring hopper with a delivery part of the delivery passage and a lower connection means 27A which connects the lower opening 21b of the measuring hopper with a feeding part of the dissolution tank. The upper opening and the delivery part are connected by means of an upper connection means and deliver powder to the measuring hopper, and the lower opening and the feeding part are connected by means of the lower connection means and feed the powder to the dissolution tank. Then, when the measuring means measures weight of the powder in the measuring hopper, respective connections are released, the upper opening and the delivery part are separated from each other, and the lower opening and the feeding part are separated from each other.
