An alpha particle contains no electrons. It is made up of two protons and two neutrons, which are closely bound together. This means that an alpha particle has a net positive charge because protons carry a positive charge while neutrons have no charge.
In essence, an alpha particle is essentially the nucleus of a helium atom, and it represents one of the most stable configurations of atomic nuclei. Because it lacks electrons, an alpha particle does not have the same electrical neutrality that you would find in a complete atom.