A mobile wireless communication terminal capable of performing data communication on the basis of a plurality of wireless communication methods with different theoretical maximum transmission speeds, said mobile wireless communication terminal comprising: first wireless communication means (2 10) which performs first data communication with an external network on the basis of a first wireless communication method, thereby to relay data transmitted between the external network and a client terminal belonging under the mobile wireless communication terminal; second wireless communication means which performs second data communication with the client terminal on the basis of a second wireless communication method, thereby to relay data transmitted between the external network and the client terminal; transmission speed grasping means which obtains a grasp of respective theoretical maximum transmission speeds of the first wireless communication method and the second wireless communication method; and transmission speed initializing means which, based on the result of the grasp by the transmission speed grasping means, sets a value according to the theoretical maximum transmission speed of the wireless communication method with the slower theoretical maximum transmission speed out of the first wireless communication method and the second wireless communication method, as an initial transmission speed for the second wireless communication means to first start the second data communication with the client terminal on the basis of the second wireless communication method; wherein, when the theoretical maximum transmission speed of the first wireless communication method is slower than the theoretical maximum transmission speed of the second wireless communication method, the transmission speed grasping means grasps at least one of a real maximum transmission speed and an average transmission speed during an operation in which the first wireless communication means performs the first data communication with the external network on the basis of the first wireless communication method, and the transmission speed initializing means sets a value according to at least one of the real maximum transmission speed and the average transmission speed as an initial transmission speed for the second wireless communication means to next or thereafter start the second data communication with the client terminal. first wireless communication means (2 10) which performs first data communication with an external network on the basis of a first wireless communication method, thereby to relay data transmitted between the external network and a client terminal belonging under the mobile wireless communication terminal; second wireless communication means which performs second data communication with the client terminal on the basis of a second wireless communication method, thereby to relay data transmitted between the external network and the client terminal; transmission speed grasping means which obtains a grasp of respective theoretical maximum transmission speeds of the first wireless communication method and the second wireless communication method; and transmission speed initializing means which, based on the result of the grasp by the transmission speed grasping means, sets a value according to the theoretical maximum transmission speed of the wireless communication method with the slower theoretical maximum transmission speed out of the first wireless communication method and the second wireless communication method, as an initial transmission speed for the second wireless communication means to first start the second data communication with the client terminal on the basis of the second wireless communication method; wherein, when the theoretical maximum transmission speed of the first wireless communication method is slower than the theoretical maximum transmission speed of the second wireless communication method, the transmission speed grasping means grasps at least one of a real maximum transmission speed and an average transmission speed during an operation in which the first wireless communication means performs the first data communication with the external network on the basis of the first wireless communication method, and the transmission speed initializing means sets a value according to at least one of the real maximum transmission speed and the average transmission speed as an initial transmission speed for the second wireless communication means to next or thereafter start the second data communication with the client terminal.