In an electronic component contained substrate in which electronic components are mounted between a pair of wiring substrates in a plural-stage stacked fashion, one wiring substrate and other wiring substrate are connected electrically mutually via solder balls, a first electronic component is mounted on one wiring substrate and then a second electronic component is mounted on the first electronic component, an opening portion for containing the second electronic component therein is provided in the other wiring substrate, the second electronic component is contained and mounted in the opening portion and is connected electrically to the other wiring substrate by a wire bonding, and a space between the pair of wiring substrates is sealed with a sealing resin.