Luggage storage facilities are available both at Amsterdam Schiphol Airport and at Amsterdam Central Station.
Amsterdam Schiphol Airport
The self service lockers cost from EUR 6.00 up to EUR 11.50 per 24 hours depending on the locker size you avail. The Baggage Depot cost EUR 7.00 per piece for 1-7 days storage or EUR 6.00 per piece for storage between 8-30 days. For more information, please visit the link: https://www.schiphol.nl/en/at-schiphol/services/luggage-storage
Amsterdam Central Station
The self-service luggage lockers are located at the east wing part of the station (on the right side if you are facing the front entrance of the station). Cost is EUR 7.00 for small lockers and EUR 10.00 for big lockers per 24 hours. Maximum length of storage is 9 days. For more information regarding the lockers, please visit this link: http://goo.gl/ZrQfva