To provide an electronic component mounting substrate that is reasonably and easily manufacturable and has excellent heat resistance and bonding reliability, and to provide a method for manufacturing the same.

An electronic component mounting substrate includes at least one printed substrate that has: an insulating substrate; and a conductor wiring layer formed on at least one surface of the insulating substrate. The electronic component mounting substrate has: a wiring substrate 1 that has a plurality of land electrodes 3 on a surface thereof; and an electronic component 7 that has a plurality of AU bump electrodes 71 on a surface thereof. The land electrodes 3 and the AU bump electrodes 71 are electrically connected through a bonding member. The bonding member includes an intermetallic compound 83 with a melting point of 300°C or more that is formed by a reaction of a first metal including Sn and a second metal 82 with a higher melting point than that of the first metal. A difference between lattice constants of the second metal 82 and the intermetallic compound 83 that is initially formed on a surface of the second metal 82 is 50% relative to more of the lattice constant of the second metal 82.