To provide an electronic component device, with which sufficient bonding reliability can be provided even when flip chip mounting of a surface acoustic wave(SAW) device on a substrate is performed.

In this electronic component device, a SAW element, with which a comb-like electrode 2 is formed on the principal side of a piezoelectric monocrystal substrate and a connecting bump is arrayed and formed around, is mounted on a substrate 6 by a face-down system. The connecting bump 4 arrayed in a direction, where mismatching between the linear expansion coefficients of the piezoelectric monocrystal substrate and the substrate is great, is located by displacing other connecting bumps 4c and 4d from a center between connecting bumps 4a and 4b positioned on both the ends of that direction.