To provide an aluminum chelate type latent curing agent which can cure thermosetting epoxy resins at relatively low temperatures in short time and a process for producing aluminum chelate type curing agents which enable relatively easy control of the curing conditions. [MEANS FOR SOLVING PROBLEMS] A latent curing agent comprising a porous resin obtained by interfacial polymerization of a polyfunctional isocyanate compound and an aluminum chelate supported on the porous resin. When the latent curing agent is used for a curable epoxy resin composition for DSC, the exothermic peak temperature inDSC of the composition containing the curing agent with the pretreatment of the agent by immersion in a nonaqueous polar solvent can be enhanced to a level higher than the exothermic peak temperaturein DSC of the composition containing the curing agent without the pretreatment of the agent by immersion in a nonaqueous polar solvent.