A method of controlling contact load in an apparatus for mounting electronic components on a substrate, in which a head is lowered at high speed to slow down starting position where there is no risk that the electronic component makes contact with the substrate (S1), and from there the head is lowered at low speed until a predetermined target contact load is detected. The process of lowering the head at low speed includes the steps of moving down the head a predetermined distance (S3), measuring load after the step of moving down the head (S5), and determining whether the measured contact load has reached the target contact load (S9). The steps of moving down the head (S3) and measuring the load (S5) are repeated until the measured load reaches the target contact load. The actual load is precisely controlled to be close to a very small set level of target contact load. Accordingly, electronic components using low dielectric constant material are mounted without the risk of damage.