You are required to leave your accommodation in the state you found it, you should be able to refer to your inventory to help you know what this is like.
It is often a good idea to give the whole property a good clean, be aware that you may be charged if you leave any rubbish or possessions in the property.
Your estate agent or landlord will come and check the property when you are moving out and may make deductions to your property or charge you if there are any damages or the property is in a worse condition than when you moved in.