(I couldn't find an up-to-date, canonical answer for this. A better question for this answer would be What is the full block reward?, but that has been duplicated to this one... )
The current issuance rate - as of the Byzantium hard-fork and EIP-649 - is set at 3 ether, reduced from the previous 5.
// Ethash proof-of-work protocol constants.
FrontierBlockReward *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
ByzantiumBlockReward *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
maxUncles = 2 // Maximum number of uncles allowed in a single block
allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks