Abstract: The invention relates to a key, in particular for an automobile, which comprises:—a casing (3) with an upper half shell (3a) defining a lid and a lower half shell (3b) defining a casing bottom;—an insert (5, 7) pivotally mounted relative to the casing (3) and capable of movement between a rest position in which the insert (5, 7) is stowed in said casing (3) and a use position in which the insert (5, 7) is extended relative to said casing (3);—an insert (5, 7) extension device mounted in the casing (3) and including: a push button (19) axially received in a cavity (21) combined with the upper half shell (3a) and protruding from the upper half shell (3a) so as to be actuated by a user; and an elastic return member (23) for the insert (5, 7), having a first end (23a) connected to the insert (5, 7) for pivotally urging the insert (5, 7) into the use position when the push button (19) is actuated.