A camera module comprising: a housing comprising a through hole; a lens module disposed in the through hole; a connector penetrating the housing and extending to an outside from an inside of the housing; a first substrate unit located inside the housing and having an image sensor mounted thereon; a second substrate unit disposed in the housing and connected to the connector; and a flexible substrate electrically connecting a second substrate portion of the first substrate unit and a third substrate portion of the second substrate unit, wherein the flexible substrate is coupled to a lower surface of the second substrate portion of the first substrate unit and a side surface of the third substrate portion of the second substrate unit, wherein the first substrate unit includes a first substrate portion including a first connecting port, the first substrate portion being mounted at an upper surface with the image sensor, the first connecting port being disposed at the bottom surface of the first substrate portion, and the second substrate portion including a second connecting port coupled to the first connecting port, and wherein the second substrate unit includes the third substrate portion including a third connecting port connected to the second substrate portion through the flexible substrate and a fourth substrate portion including a fourth connecting port coupled to the third connecting port and connected to the connector, characterized in that the first substrate portion comprises a guide hole, and characterized in that the housing comprises a guide lug protruded inwardly and inserted into the guide hole to guide a coupling position of the first substrate portion. a housing comprising a through hole; a lens module disposed in the through hole; a connector penetrating the housing and extending to an outside from an inside of the housing; a first substrate unit located inside the housing and having an image sensor mounted thereon; a second substrate unit disposed in the housing and connected to the connector; and a flexible substrate electrically connecting a second substrate portion of the first substrate unit and a third substrate portion of the second substrate unit, wherein the flexible substrate is coupled to a lower surface of the second substrate portion of the first substrate unit and a side surface of the third substrate portion of the second substrate unit, wherein the first substrate unit includes a first substrate portion including a first connecting port, the first substrate portion being mounted at an upper surface with the image sensor, the first connecting port being disposed at the bottom surface of the first substrate portion, and the second substrate portion including a second connecting port coupled to the first connecting port, and wherein the second substrate unit includes the third substrate portion including a third connecting port connected to the second substrate portion through the flexible substrate and a fourth substrate portion including a fourth connecting port coupled to the third connecting port and connected to the connector, characterized in that the first substrate portion comprises a guide hole, and characterized in that the housing comprises a guide lug protruded inwardly and inserted into the guide hole to guide a coupling position of the first substrate portion.