The landlord or agent is entitled to inspect the rental property by prior appointment. This will be clearly stated in most lease agreements.

Many agents will inspect the property every three or six months.

You are entitled to be present for the inspection at a time that is mutually convenient to both parties. Inspections are a good idea as they allow small issues to be identified and rectified before they become big issues. It allows issues to be resolved during the course of the tenancy rather than at the end when your deposit may be at risk.