To provide a consecutive reactor of an adiabatic type, which can accurately estimates capability of a catalyst being used in an actual plant of an adiabatic reactor type.

The reactor of the adiabatic type is provided with: a reaction tube having a tube in which a thermometer is inserted; an electric furnace being built from a plurality of heater blocks which are segmented in the axial direction of the reaction tube and can be thermally controlled with respect to the segments chiefly and by which the reaction tube is heated from its periphery; and an adiabator material which is disposed between the reaction tube and the electric furnace and in which a thermometer for measuring temperature values on both the reaction tube side and the electric furnace side is embedded. Therefore, the capability of the catalyst is estimated while keeping the reaction tube in an adiabatic state.