An electric connection box comprising: a housing having an opening of a polygonal shape, the opening being defined by an upper end of each of a plurality of side walls ; a lock protruding plate protruding from an outer surface of one of the plurality side walls , the one being along a side of the opening ; a lid including a hanging wall and being configured to be attached to the housing while covering the opening ; a hook having a frame shape and an inner hole ; an inner wall protruding downward from the lid and extending parallel to the hanging wall ; and a notch being obtained by cutting a lower tip end of the inner wall , wherein the hanging wall is configured, when the lid is attached to the housing , to cover an outer side of each of the plurality of side walls , wherein the hook extends downward from an outer surface of the hanging wall and is configured to rotate the lid such that the lid is attached to the housing with the inner hole being engaged with the lock protruding plate , wherein the inner wall is provided at an inner side than the hanging wall on the lid and is configured to, when the lid is attached to the housing , to sandwich the one of the plurality side walls between the hanging wall and the inner wall , and wherein the lid further includes a packing accommodating groove provided between the hanging wall and the inner wall of the lid , the packing accommodating groove being configured such that an annular packing is attached into the packing accommodating groove , characterized in that the notch is formed on the inner wall only in a second portion corresponding to a first portion of the hanging wall on which the hook is provided. a housing having an opening of a polygonal shape, the opening being defined by an upper end of each of a plurality of side walls ; a lock protruding plate protruding from an outer surface of one of the plurality side walls , the one being along a side of the opening ; a lid including a hanging wall and being configured to be attached to the housing while covering the opening ; a hook having a frame shape and an inner hole ; an inner wall protruding downward from the lid and extending parallel to the hanging wall ; and a notch being obtained by cutting a lower tip end of the inner wall , wherein the hanging wall is configured, when the lid is attached to the housing , to cover an outer side of each of the plurality of side walls , wherein the hook extends downward from an outer surface of the hanging wall and is configured to rotate the lid such that the lid is attached to the housing with the inner hole being engaged with the lock protruding plate , wherein the inner wall is provided at an inner side than the hanging wall on the lid and is configured to, when the lid is attached to the housing , to sandwich the one of the plurality side walls between the hanging wall and the inner wall , and wherein the lid further includes a packing accommodating groove provided between the hanging wall and the inner wall of the lid , the packing accommodating groove being configured such that an annular packing is attached into the packing accommodating groove , characterized in that the notch is formed on the inner wall only in a second portion corresponding to a first portion of the hanging wall on which the hook is provided. <EOS>