This work shows the comparison of the NANO VNA with a professional laboratory VNA, for tests of radio frequency (RF) and microwave devices and components, with a focus on printed circuit board substrates. The tests were carried out for three substrates: FR4 (ɛ r =4.4) TLY5 (ɛ r =2.2) y RF35 (ɛ r =3.5), obtaining a minimum error with both VNAs, so the use of the NANO VNA is a good option for students and professionals in the area of telecommunications engineering, especially because of its cost of less than 200 dollars compared to the professional VNAs of Thousands of dollars.