The invention provides a non-invasive treatment device (100) for heating a first (15) and a second (25) inner region of skin using r.f. electrical current, comprising: a first r.f. treatment electrode (10) configured and arranged to allow r.f. current to pass through the first inner region (15) to a return electrode (340), a second r.f. treatment electrode (20) configured and arranged to allow r.f. current to pass through the second inner region (25) to the return electrode (340), the device further being arranged such that the smallest distance between the first r.f. treatment electrode (10) and the return electrode (340) is less than the smallest distance between the second r.f. treatment electrode (20) and the return electrode (340); wherein the electrical skin contact area of the return electrode (340) is 5 or more times larger than the electrical skin contact area of the first r.f. treatment electrode (10), and the electrical skin contact area of the second r.f. treatment electrode (20) is 5 or more times larger than the electrical skin contact area of the first r.f. treatment electrode (10). By incorporating the second and first treatment electrodes in the same device, or probe, the positional relationship between the first and second regions being heated is fixed, or at least more predictable. By means of a suitable configuration, the regions may coincide to a smaller or greater degree. In some cases, the configuration may allow the same skin condition to be treated using heating of the first and second inner regions without moving the device over the skin. By providing an electrical skin contact area of the return electrode which is 5 or more times larger than the electrical skin contact area of the first r.f. treatment electrode, the locations heated by the r.f. electrical current will be proximate to the first treatment electrode, reducing the possibility of undesirable hotspots proximate the return electrode (340).