Operating System: Linux 64-bit, Windows 64-bit, macOS X 10.14+,
Memory: 4GB RAM
Storage: 160GB SSD
Internet: Reliable broadband connection
Note that in order to process incoming validator deposits from the eth1 chain, you will need to run an eth1 client in parallel to your eth2 client. While it is possible to use a third-party service like Infura, if you choose to run your own eth1 client locally, you'll need more memory and storage.
For example, you'll need at least another 290GB SSD to run geth fast sync on mainnet.