Internet of things is constantly growing and benefits from internet of things is helping every member of our society. Unfortunately, succeeded cyberattacks are also on the rise and that is risk for reliability of internet of things. Therefore, it is important to study what kind of threats internet of things faces and how we can protect it better. This thesis concerns how internet of things works, what kind of threats they face and how they are made secure. Thesis is made by literature re-view and sources are mostly academic peer reviewed articles. In the thesis mul-tiple cybersecurity threats, that internet of things faces, were found. These threats are physical vulnerability from physical attacks, wireless communication and low amount of computing power in the devices of internet of things. Even though many threats were found, it became clear that there are not as many direct an-swers on how to solve these threats.