An assembly, including: - an SOEC/SOFC type solid oxide cell stack operating at high temperature, including: - a plurality of electrochemical cells each formed of a cathode, an anode and an electrolyte interposed between the cathode and the anode, and a plurality of intermediate interconnectors each arranged between two adjacent electrochemical cells, - a system for clamping the SOEC/SOFC type solid oxide cell stack, including an upper clamping plate and a lower clamping plate, between which the SOEC/SOFC type solid oxide cell stack is clamped, each clamping plate (45, 46) including at least two clamping holes, the clamping system further including: - at least two clamping rods intended to each extend through a clamping hole of the upper clamping plate and through a corresponding clamping hole of the lower clamping plate to allow the assembly of the upper and lower clamping plates together, - clamping means (56, 57, 58) at each clamping hole of the upper and lower clamping plates intended to cooperate with said at least two clamping rods to allow the assembly of the upper and lower clamping plates together, characterised in that at least one of the upper and lower clamping plates includes a housing, formed in the thickness (e p) of said at least one of the upper and lower clamping plates, comprising first and second opposite ends of which at least one opens onto the lateral face of said at least one of the upper and lower clamping plates, said housing being located inside said at least one of the upper and lower clamping plates, at a distance from its upper and lower main faces, which are substantially parallel with each other, and in that the assembly includes at least one, removable and interchangeable, heating plate inserted into said housing. - an SOEC/SOFC type solid oxide cell stack operating at high temperature, including: - a plurality of electrochemical cells each formed of a cathode, an anode and an electrolyte interposed between the cathode and the anode, and a plurality of intermediate interconnectors each arranged between two adjacent electrochemical cells, - a system for clamping the SOEC/SOFC type solid oxide cell stack, including an upper clamping plate and a lower clamping plate, between which the SOEC/SOFC type solid oxide cell stack is clamped, each clamping plate (45, 46) including at least two clamping holes, the clamping system further including: - at least two clamping rods intended to each extend through a clamping hole of the upper clamping plate and through a corresponding clamping hole of the lower clamping plate to allow the assembly of the upper and lower clamping plates together, - clamping means (56, 57, 58) at each clamping hole of the upper and lower clamping plates intended to cooperate with said at least two clamping rods to allow the assembly of the upper and lower clamping plates together, - a plurality of electrochemical cells each formed of a cathode, an anode and an electrolyte interposed between the cathode and the anode, and a plurality of intermediate interconnectors each arranged between two adjacent electrochemical cells, - a system for clamping the SOEC/SOFC type solid oxide cell stack, including an upper clamping plate and a lower clamping plate, between which the SOEC/SOFC type solid oxide cell stack is clamped, each clamping plate (45, 46) including at least two clamping holes, the clamping system further including: - at least two clamping rods intended to each extend through a clamping hole of the upper clamping plate and through a corresponding clamping hole of the lower clamping plate to allow the assembly of the upper and lower clamping plates together, - clamping means (56, 57, 58) at each clamping hole of the upper and lower clamping plates intended to cooperate with said at least two clamping rods to allow the assembly of the upper and lower clamping plates together, - at least two clamping rods intended to each extend through a clamping hole of the upper clamping plate and through a corresponding clamping hole of the lower clamping plate to allow the assembly of the upper and lower clamping plates together, - clamping means (56, 57, 58) at each clamping hole of the upper and lower clamping plates intended to cooperate with said at least two clamping rods to allow the assembly of the upper and lower clamping plates together, characterised in that at least one of the upper and lower clamping plates includes a housing, formed in the thickness (e p) of said at least one of the upper and lower clamping plates, comprising first and second opposite ends of which at least one opens onto the lateral face of said at least one of the upper and lower clamping plates, said housing being located inside said at least one of the upper and lower clamping plates, at a distance from its upper and lower main faces, which are substantially parallel with each other, and in that the assembly includes at least one, removable and interchangeable, heating plate inserted into said housing.