The present invention provides a low molecular weight compound having EPO production-promoting action and/or hemoglobin production-promoting action. The present invention relates to a fused piperidine compound represented by the following general formula (1):(wherein, ring A represents a C10-14 aryl group or 5- to 10-membered heterocyclic group, ring B represents a C6-14 alkyl group, X represents N-R7, a sulfur atom or an oxygen atom, R1, R2, R2, R3 and R3 independently represent a hydrogen atom, C1-6 alkyl group or C3-6 cycloalkyl group, and R4, R5 and R6 independently represent a hydrogen atom or halogen atom), or a salt thereof, or a solvate thereof.
