A cryostat comprising: a chamber having a cooling function; and a microtome wherein the microtome includes a cutting blade which is disposed in the chamber and is attached to a blade holder; a head which holds a sample so that a front face side of the sample faces the cutting blade, the head being disposed in the chamber; an alignment mechanism which is provided on a back face side of the head and aligns said head so that the head is rotatable in a vertical direction and is rotatable in a horizontal direction perpendicular to the vertical direction; a body portion which is provided on a back face side of the alignment mechanism and has a contact separation mechanism allowing the head to contact with and separate from the cutting blade; a cylindrical coupling portion which has a hollow portion formed in its center and couples the body portion with the head; a temperature controller provided in the head for cooling or heating the sample held by the head; and refrigerant piping for circulating a refrigerant in the temperature controller, and electrical wiring for the temperature controller, wherein: said alignment mechanism includes a spherical member coupled with the back face side of the head and having a spherical outer periphery, and a retainer portion for slidably retaining the outer periphery of the spherical member along the spherical surface; in said spherical member, a through hole communicating with the hollow portion of said coupling portion is formed; and said refrigerant piping and electrical wiring are connected with the temperature controller in the head through the through hole of the spherical member and the hollow portion of the coupling portion, without being exposed to the inside of the chamber. a chamber having a cooling function; and a microtome wherein the microtome includes a cutting blade which is disposed in the chamber and is attached to a blade holder; a head which holds a sample so that a front face side of the sample faces the cutting blade, the head being disposed in the chamber; an alignment mechanism which is provided on a back face side of the head and aligns said head so that the head is rotatable in a vertical direction and is rotatable in a horizontal direction perpendicular to the vertical direction; a body portion which is provided on a back face side of the alignment mechanism and has a contact separation mechanism allowing the head to contact with and separate from the cutting blade; a cylindrical coupling portion which has a hollow portion formed in its center and couples the body portion with the head; a temperature controller provided in the head for cooling or heating the sample held by the head; and refrigerant piping for circulating a refrigerant in the temperature controller, and electrical wiring for the temperature controller, wherein: said alignment mechanism includes a spherical member coupled with the back face side of the head and having a spherical outer periphery, and a retainer portion for slidably retaining the outer periphery of the spherical member along the spherical surface; in said spherical member, a through hole communicating with the hollow portion of said coupling portion is formed; and said refrigerant piping and electrical wiring are connected with the temperature controller in the head through the through hole of the spherical member and the hollow portion of the coupling portion, without being exposed to the inside of the chamber. said alignment mechanism includes a spherical member coupled with the back face side of the head and having a spherical outer periphery, and a retainer portion for slidably retaining the outer periphery of the spherical member along the spherical surface; in said spherical member, a through hole communicating with the hollow portion of said coupling portion is formed; and said refrigerant piping and electrical wiring are connected with the temperature controller in the head through the through hole of the spherical member and the hollow portion of the coupling portion, without being exposed to the inside of the chamber.