Abstract: A cover locking device for a bait cast reel for easily detaching the cover which is assembled at one side of the reel body so as to rotatably receive one end of the spool shaft of a spool on which a fishing line is wound. The cover locking device comprises a first spring located in a first recess formed in the reel body, a locking member received in the first recess and biassed by the first spring to protrude outwardly from the first recess, and a button received in a second recess formed in an outer surface of the cover. A pressing member projects from the button and is inserted in a guide hole to contact the locking member which extends into a third recess in the cover. The guide hole connects the second and third recesses. A stopper on the pressing member prevents the pressing member from escaping from the third recess. When the button is pressed, the locking member is displaced from the third recess to unblock rotation of the cover and enable its unlatching from the reel body.