A case structure for card-type electronic product includes an intermediate frame having insertion slots spaced thereon; a lower cover connected to a lower side of the intermediate frame by lower hooking members upward inserted into the insertion slots, and each of the lower hooking members including two spaced latch legs; and an upper cover connected to an upper side of the intermediate frame by upper hooking members downward inserted into the insertion slots corresponding to the lower hooking members, and each of the upper hooking members including two laterally outward extended latch hooks. When the upper and lower covers are assembled to the upper and lower sides of the intermediate frame, the latch hooks of the upper hooking members are abutted on lower edges of the latch legs of the lower hooking members to firmly hold the lower cover to the upper cover in three directions.