Security plays a prime concern in our day-today life. Everyone wants to be as much secure as possible and why not the place we study. So we planned to create a project which is helpful to our classroom. Our department JKE uses keys to lock classroom door after the class hour. We found that it is less secured and keys may lose easily. The Arduino based door locker is an access control system that allows only authorized persons to access the classroom in restricted time and day. The system is fully controlled by the Arduino for the program memory. We able to use the classroom from 8am to 5pm where usually class occurring time. At 5pm the admin have to on the system. Once the system is turned on there will be notify in LCD “ENTER PASSWORD”. The users have to insert the password to access in. when they entered password equals with the passwords to reading the memory then the Arduino gets on and send signal to solenoid so that the door is opened. The password is stored in the EPROM so that we can change it at any time. The system has a keypad by which the password can be entered through. We can enter a password according to the user. We have set 3 users with different password. When user 1 entered the right password then the access is approved by showing user 1 and door is open in LCD. If we entered a wrong password, the system will not open the door and it show in LCD “PASSWORD IS INCORRECT” and buzzer is on and make sound. Only a successful password can be accessed in. Apart that, once the door then the after few seconds the buzzer will make sound and there will be a notify in LCD “please close the door” which give alert to the users to not forget to close the door.