The invention reduces a flow of a heat making an intrusion into an NMR probe, and uniformizes a spatial temperature generated in a sample pipe. A temperature modulated gas is supplied to a thermal anchor temperature modulated gas flow path constituted by a sample pipe insertion port around a sample pipe, and sample pipe insertion port structure bodies. A part of the temperature modulated gas is divided into a thermal anchor temperature modulated gas flow path by a temperature modulated gas division hole, and flows toward a thermal anchor. The thermal anchor is constituted by a porous member having a hole through which a gas can pass, and comes to the same temperature as the temperature modulated gas on the basis of a heat exchange with the temperature modulated gas. Further, since the thermal anchor is provided in a path of a heat flow making an intrusion into the sample pipe from an external portion, it is possible to absorb the heat intruding from the external portion by the temperature modulated gas passing through the thermal anchor, and it is possible to stably keep the temperature of the sample pipe.