---
title: ControlModifier (v1.0)
description: API reference for qiskit.circuit.ControlModifier in qiskit v1.0
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/1.0/qiskit.circuit.ControlModifier
---

# ControlModifier

*class* `qiskit.circuit.ControlModifier(num_ctrl_qubits=0, ctrl_state=None)`

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/1.0/qiskit/circuit/annotated_operation.py#L39-L49)

Bases: `Modifier`

Control modifier: specifies that the operation is controlled by `num_ctrl_qubits` and has control state `ctrl_state`.

## Attributes

### ctrl\_state

Type: `int | str | None`

Default value: `None`

### num\_ctrl\_qubits

Type: `int`

Default value: `0`