To provide a planar mounting type coil component, such as a planar mounting type transformer suited especially to a hybrid IC and having an extremely low height dimension.

This planar packaging type transformer 50 is provided with a ferrite core 35, having a flat wiring core part 31 in which the ratio t/w of a thickness dimension (t) to a width dimension (w) is ≤1/3, and collar parts 32, 33 extended integrally with the winding core part 31 on both the lengthwise direction ends of the winding core part 31; four electrode layers 38 arranged around a peripheral surface including at least height direction side faces 36 of the collar parts 32, 33 of the core 35 and separated from each other; and a winding 39 wound around the winding core part 31 of the core 35 and conductively fixing its both end parts to the electrode layer parts 38' of the side faces 36 which are obliquely derived to the side faces of the collar parts 32, 33 by thermocompression bonding. The transformed is further constituted as a microminiaturized and extremely flat face mrounting transformer, having about 1.2 mm height dimension H with respect to 3.6 mm total width dimension W and about 5.5 mm winding shaft length dimension L, so as to be suited to mounting on a hybrid IC.