A module that is intended to form a unit cell of an electrolysis or co-electrolysis reactor of the SOEC type, comprising: - a unit electrochemical cell formed from a cathode (2.1), an anode (4.1), and an electrolyte (3.1) inserted between the cathode and the anode, - a first device (5.1) and a second device (5.2), each forming an electrical and fluidic interconnector, each consisting of a component made of electron-conducting material and impervious to gases; the first and second interconnectors being arranged on either side of the unit cell; the first interconnector (5.1) having a steam supply line passing through it, opening onto the cell on the cathode side (2.1), and a line for recovery of the hydrogen produced, opening on the periphery of the cell on the cathode side so as to provide uniform distribution of the steam supplied and of the hydrogen produced, respectively, from the supply line to the recovery line; the second interconnector (5.2) having a recovery line for the oxygen produced passing through it, opening on the periphery of the cell on the anode side (4.1) so as to provide uniform distribution of the oxygen produced to the recovery line; - a first seal arranged at the periphery of the unit cell and resting both against the first interconnector and against the second interconnector; - a second seal arranged at the periphery of the anode of the unit cell and resting both against the second interconnector and against the electrolyte; the first and second seals being based on glass and/or glass-ceramic; - an insulating and sealing device consisting of an electrically insulating washer clamped by a third seal and a fourth seal that are not in contact with one another, the third and fourth seals being made of metal, the device being arranged at the periphery of the first seal with the third and fourth seals resting against the first interconnector and against the second interconnector, respectively; module in which the first and/or second interconnectors has (have) at least one supply line and at least one recovery line for a gas, called equalization gas, passing through it (them), each opening into the annular space delimited between the first seal and the insulating and sealing device so as to provide uniform distribution of the equalization gas from its supply line to its recovery line, in order to equalize the pressures on either side of the first seal while the reactor is operating under pressure. - a unit electrochemical cell formed from a cathode (2.1), an anode (4.1), and an electrolyte (3.1) inserted between the cathode and the anode, - a first device (5.1) and a second device (5.2), each forming an electrical and fluidic interconnector, each consisting of a component made of electron-conducting material and impervious to gases; the first and second interconnectors being arranged on either side of the unit cell; the first interconnector (5.1) having a steam supply line passing through it, opening onto the cell on the cathode side (2.1), and a line for recovery of the hydrogen produced, opening on the periphery of the cell on the cathode side so as to provide uniform distribution of the steam supplied and of the hydrogen produced, respectively, from the supply line to the recovery line; the second interconnector (5.2) having a recovery line for the oxygen produced passing through it, opening on the periphery of the cell on the anode side (4.1) so as to provide uniform distribution of the oxygen produced to the recovery line; - a first seal arranged at the periphery of the unit cell and resting both against the first interconnector and against the second interconnector; - a second seal arranged at the periphery of the anode of the unit cell and resting both against the second interconnector and against the electrolyte; the first and second seals being based on glass and/or glass-ceramic; - an insulating and sealing device consisting of an electrically insulating washer clamped by a third seal and a fourth seal that are not in contact with one another, the third and fourth seals being made of metal, the device being arranged at the periphery of the first seal with the third and fourth seals resting against the first interconnector and against the second interconnector, respectively;