A double-lock connector includes a connector housing having terminal receiving chambers, metal terminals for being inserted respectively into the terminal receiving chambers, and a terminal retainer connectable to a rear end portion of the connector housing in a two-stage manner, that is, in a provisionally-connected condition and a completely-connected condition, wherein even when the terminal retainer in the provisionally-connected condition, the metal terminal can be smoothly inserted into the connector housing. The double-lock connector of the present invention includes a connector housing and a terminal retainer for being inserted into the connector housing. The connector housing has a plurality of terminal receiving chambers which are separated from one another by a horizontal partition wall and a vertical partition wall. An elastic retaining piece is provided within each of the terminal receiving chambers. A rearwardly-extending tongue-like terminal guide piece is formed on the horizontal partition wall, separating the upper and lower terminal receiving chambers from each other, and is disposed centrally with the width of each terminal receiving chamber. A front end of the terminal guide piece is extended substantially to an inlet end of the connector housing.