A mobile station (UE), comprising: a control unit configured to manage a reception state of the mobile station (UE) as any one of a continuous reception state, a first discontinuous reception state in which discontinuous reception is performed in a first discontinuous reception cycle and a second discontinuous reception state in which discontinuous reception is performed in a second discontinuous reception cycle which is a cycle longer than the first discontinuous reception cycle, wherein in a case where the reception state of the mobile station (UE) is managed as the continuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the first discontinuous reception state when fulfillment of a first condition being an expiration of a drx-InactivityTimer is detected, in a case where the reception state of the mobile station (UE) is managed as the first discontinuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the second discontinuous reception state when fulfillment of a second condition being an expiration of a Short DRX timer is detected, the mobile station further comprising: a reception unit configured to receive a Media Access Control-Control Element, MAC-CE from a radio base station (eNB), and in a case where the reception state of the mobile station (UE) is managed as the continuous reception state, and even in a case where the reception state of the mobile station (UE) is configured to be capable of transitioning to the first discontinuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the second discontinuous reception state without transitioning the reception state to the first discontinuous reception state when an instruction to transition the reception state of the mobile station (UE) to the second discontinuous reception state is made via the MAC-CE by the radio base station (eNB). a control unit configured to manage a reception state of the mobile station (UE) as any one of a continuous reception state, a first discontinuous reception state in which discontinuous reception is performed in a first discontinuous reception cycle and a second discontinuous reception state in which discontinuous reception is performed in a second discontinuous reception cycle which is a cycle longer than the first discontinuous reception cycle, wherein in a case where the reception state of the mobile station (UE) is managed as the continuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the first discontinuous reception state when fulfillment of a first condition being an expiration of a drx-InactivityTimer is detected, in a case where the reception state of the mobile station (UE) is managed as the first discontinuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the second discontinuous reception state when fulfillment of a second condition being an expiration of a Short DRX timer is detected, the mobile station further comprising: a reception unit configured to receive a Media Access Control-Control Element, MAC-CE from a radio base station (eNB), and in a case where the reception state of the mobile station (UE) is managed as the continuous reception state, and even in a case where the reception state of the mobile station (UE) is configured to be capable of transitioning to the first discontinuous reception state, the control unit is configured to transition the reception state of the mobile station (UE) to the second discontinuous reception state without transitioning the reception state to the first discontinuous reception state when an instruction to transition the reception state of the mobile station (UE) to the second discontinuous reception state is made via the MAC-CE by the radio base station (eNB). <EOS>