A roller bearing device, with: a first bearing ring; a second bearing ring; a bearing roller (14; 14A); and a state detection device that detects a physical state of the bearing roller (14, 14A) that is rollably disposed between the first bearing ring and the second bearing ring that is disposed concentrically with the first bearing ring, the state detection device comprising: a sensor (40; 75) that detects the physical state of the bearing roller (14; 14A); and a, processing portion that obtains a detection signal that is output from the sensor (40; 75), performs processing on the detection signal, and transmits detection data obtained by performing the processing on the detection signal, to an outside, wherein the sensor (40; 75) and the processing portion are accommodated in a central hole (22; 74) formed at an axis center of the bearing roller; wherein the processing portion is provided on a substrate, and the substrate is accommodated in the central hole in a state in which the substrate is not in contact with an inner surface (22a; 74a) of the bearing roller (14; 14A), the inner surface (22a; 74a) defining the central hole (22; 74); characterized in that said substrate is retained within that central hole (22, 74) by a substrate retaining material as an elastic body and formed of a material having a rigidity lower than rigidity of the substrate so as to be configured to suppress transmission of stress or vibration acting on the tapered roller to the substrate, said substrate retaining material being interposed between the substrate and the inner surface (22a; 74a) defining the central hole (22; 74) and retaining the substrate in the state in which the substrate is not in contact with the inner surface (22a; 74a) defining the central hole (22; 74), there. a first bearing ring; a second bearing ring; a bearing roller (14; 14A); and a state detection device that detects a physical state of the bearing roller (14, 14A) that is rollably disposed between the first bearing ring and the second bearing ring that is disposed concentrically with the first bearing ring, the state detection device comprising: a sensor (40; 75) that detects the physical state of the bearing roller (14; 14A); and a, processing portion that obtains a detection signal that is output from the sensor (40; 75), performs processing on the detection signal, and transmits detection data obtained by performing the processing on the detection signal, to an outside, wherein the sensor (40; 75) and the processing portion are accommodated in a central hole (22; 74) formed at an axis center of the bearing roller; wherein a sensor (40; 75) that detects the physical state of the bearing roller (14; 14A); and a, processing portion that obtains a detection signal that is output from the sensor (40; 75), performs processing on the detection signal, and transmits detection data obtained by performing the processing on the detection signal, to an outside, wherein the sensor (40; 75) and the processing portion are accommodated in a central hole (22; 74) formed at an axis center of the bearing roller; wherein the processing portion is provided on a substrate, and the substrate is accommodated in the central hole in a state in which the substrate is not in contact with an inner surface (22a; 74a) of the bearing roller (14; 14A), the inner surface (22a; 74a) defining the central hole (22; 74); characterized in that said substrate is retained within that central hole (22, 74) by a substrate retaining material as an elastic body and formed of a material having a rigidity lower than rigidity of the substrate so as to be configured to suppress transmission of stress or vibration acting on the tapered roller to the substrate, said substrate retaining material being interposed between the substrate and the inner surface (22a; 74a) defining the central hole (22; 74) and retaining the substrate in the state in which the substrate is not in contact with the inner surface (22a; 74a) defining the central hole (22; 74), there.