Wash zucchini and cut them (without peeling) in 2 mm thick (preferably with a mandolin).
Place the zucchini slices on a paper towel, cover with a second sheet and press to absorb the maximum amount of water.
Cover with greaseproof paper a baking sheet. Place the slices of zucchini in a single layer. Brush with oil and sprinkle lightly with salt (better add more salt later).
Bake 2 hours at 100°C/212°F (the chips begin to brown and are crunchy). Let cool to serve. These chips will keep 3 days in an airtight container.