A gas-phase hydrogen permeation test device for feeding high-pressure hydrogen to one face of a test piece and analyzing hydrogen permeating through the test piece and released from another face of the test piece, the gas-phase hydrogen permeation test device comprising: a high-pressure hydrogen feeder configured to feed high-pressure hydrogen to the one face of the test piece; an analyzer configured to analyze hydrogen released from the other face of the test piece; a primary-side pipe configured to connect the high-pressure hydrogen feeder to the one face of the test piece; a secondary-side pipe configured to connect the other face of the test piece to the analyzer; a secondary-side pressure gauge configured to measure pressure inside the secondary-side pipe; a primary-side shut-off valve provided in the primary-side pipe and configured to close the primary-side pipe when placed in a closed state; a primary-side discharge valve provided downstream of the primary-side shut-off valve in the primary-side pipe and configured to provide communication between the inside and outside of the primary-side pipe when placed in an open state; a secondary-side discharge valve provided in the secondary-side pipe and configured to provide communication between the inside and outside of the secondary-side pipe when placed in an open state; a passive discharger (53, 54) provided in the secondary-side pipe; a secondary-side shut-off valve provided downstream of the secondary-side discharge valve and the passive discharger (53, 54) in the secondary-side pipe and configured to close the secondary-side pipe when placed in a closed state; and a controller configured to, when the pressure measured by the secondary-side pressure gauge reaches or exceeds a specific value, place the primary-side shut-off valve and the secondary-side shut-off valve into a closed state and the primary-side discharge valve and the secondary-side discharge valve into an open state, wherein the primary-side shut-off valve, the primary-side discharge valve, and the secondary-side discharge valve are air-operated valves, the passive discharger (53, 54) is either or both of (i) a safety valve which is configured to be placed into an open state when the pressure inside the secondary-side pipe reaches or exceeds a specific value, and provide communication between the inside and outside of the secondary-side pipe, and (ii) a rupture disc which is configured to rupture when the pressure inside the secondary-side pipe reaches or exceeds a specific value, and provide communication between the inside and outside of the secondary-side pipe, the high-pressure hydrogen feeder, the primary-side pipe, the primary-side shut-off valve, the primary-side discharge valve, the passive discharger (53, 54), the test piece, and the secondary-side discharge valve are installed in an explosion-proof environment, and the analyzer is installed in a non-explosion-proof environment. a high-pressure hydrogen feeder configured to feed high-pressure hydrogen to the one face of the test piece; an analyzer configured to analyze hydrogen released from the other face of the test piece; a primary-side pipe configured to connect the high-pressure hydrogen feeder to the one face of the test piece; a secondary-side pipe configured to connect the other face of the test piece to the analyzer; a secondary-side pressure gauge configured to measure pressure inside the secondary-side pipe; a primary-side shut-off valve provided in the primary-side pipe and configured to close the primary-side pipe when placed in a closed state; a primary-side discharge valve provided downstream of the primary-side shut-off valve in the primary-side pipe and configured to provide communication between the inside and outside of the primary-side pipe when placed in an open state; a secondary-side discharge valve provided in the secondary-side pipe and configured to provide communication between the inside and outside of the secondary-side pipe when placed in an open state; a passive discharger (53, 54) provided in the secondary-side pipe; a secondary-side shut-off valve provided downstream of the secondary-side discharge valve and the passive discharger (53, 54) in the secondary-side pipe and configured to close the secondary-side pipe when placed in a closed state; and a controller configured to, when the pressure measured by the secondary-side pressure gauge reaches or exceeds a specific value, place the primary-side shut-off valve and the secondary-side shut-off valve into a closed state and the primary-side discharge valve and the secondary-side discharge valve into an open state, wherein the primary-side shut-off valve, the primary-side discharge valve, and the secondary-side discharge valve are air-operated valves, the passive discharger (53, 54) is either or both of (i) a safety valve which is configured to be placed into an open state when the pressure inside the secondary-side pipe reaches or exceeds a specific value, and provide communication between the inside and outside of the secondary-side pipe, and (ii) a rupture disc which is configured to rupture when the pressure inside the secondary-side pipe reaches or exceeds a specific value, and provide communication between the inside and outside of the secondary-side pipe, the high-pressure hydrogen feeder, the primary-side pipe, the primary-side shut-off valve, the primary-side discharge valve, the passive discharger (53, 54), the test piece, and the secondary-side discharge valve are installed in an explosion-proof environment, and the analyzer is installed in a non-explosion-proof environment.