To provide a joined body which does not sacrifice a shape and properties of each component, has high joint reliability and can withstand practical use.

The joined body includes two or more precision components joined to each other. At least one of the precision components is formed of an alloy having an amorphous phase as a main phase. In the joined body of precision components, a joining base material, which is represented by a compositional formula shown by general formula (1), and melts in a temperature zone of a crystallization temperature or below of the alloy having the amorphous phase as the main phase, is used in a joint interface. Alternatively, in the joined body of precision components, a foil layer containing at least one of Au, Pt, Pd, and Ni is used on a joint interface side of a member formed of an alloy having an amorphous phase as a main phase, and a joining base material represented by a compositional formula shown by general formula (1) is used on a joint interface. General formula (1) is shown by: Au100-xMx wherein M represents any group of elements indispensably including at least one of Si, Ge, and Sn; and x is atom% and meets a requirement of 17.5≤x≤40.