A toner container for installation in a toner supply device is provided. The toner container includes a toner accommodation member and a cap member freely attachable to and detachable from the toner accommodation member. The toner accommodation member includes a bag member having an opening, and a connection member attached to the opening of the bag member and having a toner supply opening. The cap member is configured to receive toner supplied from the toner supply opening of the connection member of the toner accommodation member and to discharge the received toner. Either of the connection member of the toner accommodation member and the cap member includes a groove part and the other includes a protrusion part to engage with the groove part, and the cap member is attached to the toner accommodation member by engaging the groove part and the protrusion part with each other. The protrusion part elastically deforms to engage with the groove part.