Hydrogen permeability testing device

A hydrogen permeability testing device, comprising:

• a metal specimen comprising a hydrogen entry face through which hydrogen enters, a hydrogen detection face on which the entered hydrogen is detected, and a metal plating formed on the hydrogen detection face to detect the entered hydrogen;
• a reference electrode and a first counter electrode configured for making an electrochemical reaction progress;
• a first electrolytic vessel provided on a side of the hydrogen detection face, housing the reference electrode and the first counter electrode, and comprising an aqueous sodium silicate solution having a freezing point of 0° C. or lower, wherein a concentration of the sodium silicate in the aqueous sodium silicate solution is 70% by mass or higher;
• a second electrolytic vessel provided on a side of the hydrogen entry face housing a second counter electrode and no reference electrode;
• and
• a measurement unit configured to measure an amount of the hydrogen based on a current value resulting from the electrochemical reaction progress.