A hydrogen purification device configured such that a source gas can be supplied and from which a purified gas can flow out, comprising: a hydrogen permeable membrane allowing hydrogen to selectively permeate therethrough; two porous supports (12, 121, 122) that sandwich and support the hydrogen permeable membrane from both surfaces thereof; and a casing (13, having a space formed therein configured to accommodate reaction of the source gas and the hydrogen permeable membrane; wherein: the porous supports (12, 121, 122) are contained inside the casing; an outermost edge of the hydrogen permeable membrane extends outward from the outer edges of the porous supports (12, 121, 122) in at least one location; and a peripheral portion of the hydrogen permeable membrane in a vicinity of the outermost edge and the casing are airtightly sealed to each other, wherein one of the two porous supports is a first porous support which supports the hydrogen permeable membrane from an inflow side of the source gas and the other of the two porous supports is a second porous support which supports the hydrogen permeable membrane from an outflow side of the purified gas, between the first porous support and the casing, a source gas inflow space into which the source gas can flow is provided, a source gas supply port for supplying the source gas and a source gas discharge port for discharging the source gas not permeating through the hydrogen permeable membrane are provided in the casing, one of the source gas supply port and the source gas discharge port opens toward a first containing space containing the first porous support and the other of the source gas supply port and the source gas discharge port opens toward the source gas inflow space, and the device is characterized in that around the one of the source gas supply port and the source gas discharge port, a barrier wall which partitions between the source gas inflow space and the source gas supply port or the source gas discharge port is provided in contact with the first porous support. a hydrogen permeable membrane allowing hydrogen to selectively permeate therethrough; two porous supports (12, 121, 122) that sandwich and support the hydrogen permeable membrane from both surfaces thereof; and a casing (13, having a space formed therein configured to accommodate reaction of the source gas and the hydrogen permeable membrane; wherein: the porous supports (12, 121, 122) are contained inside the casing; an outermost edge of the hydrogen permeable membrane extends outward from the outer edges of the porous supports (12, 121, 122) in at least one location; and a peripheral portion of the hydrogen permeable membrane in a vicinity of the outermost edge and the casing are airtightly sealed to each other, the porous supports (12, 121, 122) are contained inside the casing; an outermost edge of the hydrogen permeable membrane extends outward from the outer edges of the porous supports (12, 121, 122) in at least one location; and a peripheral portion of the hydrogen permeable membrane in a vicinity of the outermost edge and the casing are airtightly sealed to each other, wherein one of the two porous supports is a first porous support which supports the hydrogen permeable membrane from an inflow side of the source gas and the other of the two porous supports is a second porous support which supports the hydrogen permeable membrane from an outflow side of the purified gas, between the first porous support and the casing, a source gas inflow space into which the source gas can flow is provided, a source gas supply port for supplying the source gas and a source gas discharge port for discharging the source gas not permeating through the hydrogen permeable membrane are provided in the casing, one of the source gas supply port and the source gas discharge port opens toward a first containing space containing the first porous support and the other of the source gas supply port and the source gas discharge port opens toward the source gas inflow space, and the device is characterized in that around the one of the source gas supply port and the source gas discharge port, a barrier wall which partitions between the source gas inflow space and the source gas supply port or the source gas discharge port is provided in contact with the first porous support.