An aluminum chelate-based latent curing agent is provided which can cure a thermosetting epoxy resin at a relatively low temperature in a short period of time. A method for producing such an aluminum chelate-based latent curing agent, whose curing conditions can be relatively easily controlled, is also provided. The aluminum chelate-based latent curing agent is made latent by reacting a silsesquioxane-type oxetane derivative with an aluminum chelating agent in the presence of an alicyclic epoxy compound.