A container cap comprising: a body part coupled to a container inlet of a container containing contents and having an opening at an upper side thereof; a cover part coupled to the body part to open and close the upper opening of the body part; and a separation part integrally connected to a first member that is any one of the body part and the cover part by a first connection part and integrally and separably connected to a second member that is the other one of the body part and the cover part by a second connection part, wherein the second connection part is separated by user's manipulation so that the cover part is separable from the body part, wherein the first member is provided with a fixing part for fixing the separation part after the separation part is separated from the second member, wherein the separation part connects the body part to the cover part in a vertical direction, wherein the container cap is made of a plastic material, and the first connection part is formed as a thin film, and the second connection part is formed as a cut groove or a plurality of bridges, wherein the separation part is fitted into the fixing part so as to be fixed to the fixing part, wherein, in the separation part, the first connection part is folded vertically to be coupled to the fixing part, wherein the fixing part comprises one or more second fitting part formed on an outer circumferential surface of the first member and fitted with one or more first fitting part provided in the separation part wherein in the body part, a concave groove having a shape corresponding to a front shape of the separation part is formed to be recessed, and wherein the cover part includes an inner ring which protrudes from the bottom surface and is inserted into the inner circumferential surface of the container inlet in order to increase in sealing force of the container. a body part coupled to a container inlet of a container containing contents and having an opening at an upper side thereof; a cover part coupled to the body part to open and close the upper opening of the body part; and a separation part integrally connected to a first member that is any one of the body part and the cover part by a first connection part and integrally and separably connected to a second member that is the other one of the body part and the cover part by a second connection part, wherein the second connection part is separated by user's manipulation so that the cover part is separable from the body part, wherein the first member is provided with a fixing part for fixing the separation part after the separation part is separated from the second member, wherein the separation part connects the body part to the cover part in a vertical direction, wherein the container cap is made of a plastic material, and the first connection part is formed as a thin film, and the second connection part is formed as a cut groove or a plurality of bridges, wherein the separation part is fitted into the fixing part so as to be fixed to the fixing part, wherein, in the separation part, the first connection part is folded vertically to be coupled to the fixing part, wherein the fixing part comprises one or more second fitting part formed on an outer circumferential surface of the first member and fitted with one or more first fitting part provided in the separation part wherein in the body part, a concave groove having a shape corresponding to a front shape of the separation part is formed to be recessed, and wherein the cover part includes an inner ring which protrudes from the bottom surface and is inserted into the inner circumferential surface of the container inlet in order to increase in sealing force of the container.