A connection port (31) in a dialysis apparatus (1) comprising: a cylindrical outer port (42) to which is connected a discharge side pipe of fluid (30b)； an inner port (43) to which is connected a pipe side liquid supply (30a) and provided on the outer port (42)； and a lid member (44) which closes the outer port (42), a liquid from the inside port (43) can flow through a space formed by the lid member (44) and the outer port (42) and downloadable from the external port (42) when the lid member (44) is in a closed state, the inner port (43) being exposed to the outside when the lid member (44) is in an open state, allowing connecting a liquid conduit into port (43), characterized in that: the outer port (42) is in the form of a bottomed cylinder and is provided with an opening which is closed by the lid member (44) having the form of a bottomed cylinder； inside port (43) has an end portion projecting outside the opening of the outer port (42), and is fixed to the outer port (42) to penetrate a lower portion of the outer port (42) from the outside to the inside and also a heater (H) for a portion of the inner port (43) projecting beyond the outer port (42) is provided； and when the lid member (44) is in the closed state, the inner port (43) is heated with the heater (H) for sterilizing the portion of the inner port (43) exposed to the outsideUn puerto de conexión (31) en un aparato de diálisis (1) que comprende: un puerto exterior cilíndrico (42) al que está conectada una tubería del lado de descarga de líquido (30b)； un puerto interior (43) al que está conectada una tubería del lado de suministro de líquido (30a) y que se proporciona en el puerto exterior (42)； y un elemento de tapa (44) que cierra el puerto exterior (42), un líquido desde el puerto interior (43) que puede fluir a través de un espacio formado por el elemento de tapa (44) y el puerto exterior (42) y descargable desde el puerto exterior (42) cuando el elemento de tapa (44) está en un estado cerrado, est
